title: Hybrid hydroxyapatite nanoparticle colloidal gels are injectable fillers for bone tissue engineering.
abstract: Injectable bone fillers have emerged as an alternative to the invasive surgery often required to treat bone defects. Current bone fillers may benefit from improvements in dynamic properties such as shear thinning during injection and recovery of material stiffness after placement. Negatively charged inorganic hydroxyapatite (HAp) nanoparticles (NPs) were assembled with positively charged organic poly(d,l-lactic-co-glycolic acid) (PLGA) NPs to create a cohesive colloidal gel. This material is held together by electrostatic forces that may be disrupted by shear to facilitate extrusion, molding, or injection. Scanning electron micrographs of the dried colloidal gels showed a well-organized, three-dimensional porous structure. Rheology tests revealed that certain colloidal gels could recover after being sheared. Human umbilical cord mesenchymal stem cells were also highly viable when seeded on the colloidal gels. HAp/PLGA NP colloidal gels offer an attractive scheme for injectable filling and regeneration of bone tissue.
authors.affiliation: 1 Department of Chemical and Biological Engineering, Iowa State University , Ames, Iowa.
authors.forename: Qun
authors.initials: Q
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Gu
authors.forename: Syed
authors.initials: S
authors.lastname: Jamal
authors.forename: Michael S
authors.initials: MS
authors.lastname: Detamore
authors.forename: Cory
authors.initials: C
authors.lastname: Berkland
mesh_terms: D001861:Bone Regeneration; D018786:Bone Substitutes / Q000737:chemistry*; D002478:Cells, Cultured; D003102:Colloids; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D023822:Tissue Engineering; D014470:Umbilical Cord / Q000166:cytology* / Q000378:metabolism
chemical_list: D018786:Bone Substitutes; D003102:Colloids; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017886:Durapatite